Steering indicator for mining machines



Jan. 19, 1954 J. B. MAVOR STEERING INDICATOR FOR MINING MACHINES Filed March 4, 1950 I a In ventor Jb/IM/m/ZM we A ilorneys the guide bars 9, l sliding through the now stationary carriage 14. The head 13 now performs its cutting stroke. Thereafter the jack is 0perated so that its head is lowered and its foot raised, thus contracting the jack and freeing it from the roof and floor. Finally, the ram unit is operated so that the ram I9 is forced to the left, the ram thus engaging the rear wall 1' and pushing the carriage ll so that it freely slides to the right hand end of the guide bars 9, lil to take up a new position of anchorage for the next cutting stroke. This completes the cycle of operations.

In the example, each cutterjhead comprises a leading cutter 20 arranged at an intermediate level, two cutters 2| and 22 above the cutter 20, a floor cutter 23 and a roof cutter 24. The floor cutter is associated with a sloping ramp 23C for lifting the coal from the floor and deflecting it sidewise from the path of the machine for conveyance from the mine workings.

Seeing thatthe machine is double-ended, being designed for travel in both directions, it is provided with two indexes in the form of two short vertical posts 25, 26 fixed in longitudinal alignment one at each end of the machine, namely on the end walls I and 8 of the body of the machine, these posts constituting light masks. A mirror 21 is arranged on the carriage ll, being therefore about the middle of the machines length. The mirror is pivotally mounted so that it can be set in either of two positions in which it is inclined at 45 to the longitudinal axis of the machine; for instance, the axis of the guide bar 9. Therefore, the mirror is set facing forwards so as to reflect the post 25 or 26 ahead of it laterally outwards to the eye of the operator, who occupies a stance in front of the carriage H; that is, the outer side opposite the newly cut coal face C (Fig. 2). The mirror face is marked with a vertical strip 28 constituting a marker, and

this strip lies in the vertical longitudinal plane of the posts 25, 26. The arrangement is such that when the operator is sighting during steering, he sees the reflection of the ahead post 25 I shield 29 which is open or windowed at its outer end 30 and at 3! in both sides.

In use of the machine any appropriate signal, preferably a coloured incandescent electric lamp 32, is provided as an objective to be sighted by the operator, being set at that end of the seam D towards which the machine has to work. The lamp is set at an appropriate level, and at such a distance from the face E to be cutinto, that the lamp occupies what may be termed the sighting line F, which extends horizontally in the longitudinal plane along which the machine is to be steered. Thus, so long as the machine is working along the proper line oftravel, represented by the line F, the ray of light G from the lamp 32 will be masked from the operator when he sights; that is, when he looks through the shield 29 into the mirror 21, keeping the reflection of the mask post 26 in register with the marker stri 28. If however the machine should deviate from the proper line F, the operator at once sees the reflection H of the light signal 32 and knows to steer the machine back to the proper line of travel.

In the machine shown as an example, no means is provided whereby the operator can steer it.

Should therefore the machine work itself out of the proper line of travel along the sighting line F, the mine-workers can interpose one or more jacks between any appropriate part of the machine and the newly cut face 0 and by manipulating the jack or jacks they can slew the machine into the proper setting for working along, or for returning to, the proper line of travel. It is expedient for the operator to sight the steering indicator 26, 21, 28 and 32 at that time in the cycle of operations immediately after each working stroke of the head '3 is completed, the carriage ll being then at the rear end, that is the left hand end, 0f the slideway 9, l8 and the jack components l4--I'| being contracted free of the floor A and roof B. The mirror 2! is then at its maximum distance from the marker 25, which is the best condition for sighting, and the machine can then be slewed without obstruction from the jack components l4--l'l.

When the machine is operated to travel in the opposite direction, that is from right to left with the head l2 leading, the mirror 27 is angularly adjusted through so that it faces the head [2 at an inclination of 45 to the longitudinal axis of the machine.

I claim:

1. For a mining machine of the type comprising a body with a cutter head for wedging off mineral from the face of a seam in a mine, means for propelling the machine along said face in a predetermined straight path of travel towards an objective and a carriage which carries said propelling means and which is guided to move relatively to said body in opposite directions along the body, a steering indicator comprising an index arranged at a forward location on the machine body and a mirror arranged on said carriage at a location longitudinally aligned with said index but spaced rearwardly therefrom to an extent which varies with the two-directional relative movements of the carriage, said mirror being set at an inclination so as to face partly forwards towards the index and laterally outwards towards an operator in order to reflect both the objective and the index to the operator when the machine is being steered along said path.

2. A steering indicator according to claim 1 including also a marker which is combined with the mirror to register with the reflection of the objective.

3. A steering indicator according to claim 1 including also a light shield in which the mirror is mounted and through which the operator sights during steering.

4. A steering indicator according to claim 1 in which the machine for which the indicator is suited is double-ended, having cutter heads at opposite ends, and in which the mirror is pivotally mounted on the carriage so as to be angularly adjustable between positions in each of which it faces ahead at an inclination.

5. For a mining machine of the type comprising a frame, a cutter head thereon for wedging off mineral from the face of a seam in a mine, a carriage guided for movement longitudinally of said frame, means on said carriage for tempo rarily anchoring it in the mine and means on said carriage co-operating with said frame for propelling the machine step-wise along said face in a predetermined straight path of travel towards an objective, a steering indicator comprising an index arranged at a forward location on said frame and a mirror arranged on said carriage at a location longitudinally aligned with said index but spaced rearwardly therefrom, said mirror being set at an inclination so as to face partly forwards towards the index and laterally outwards towards an operator in order to reflect both. the objective and the index to the operator when the machine is being steered along said path.

6. A steering indicator according to claim 5 including also a marker which is combined with the mirror to register with the reflection of the objective.

7. A steering indicator according to claim 5 including also a light shield in which the mirror is mounted and through which the operator sights during steering.

8. A steering indicator according to claim 5 in which the machine for which the indicator is suited is double-ended, having cutter heads at opposite ends or the frame, and in which the 6 mirror is pivotally mounted on the carriage so as to be angularly adjustable between positions in each of which it faces ahead at an inclination.

JOHN BRIDIE MAVOR.

References Cited in the file Of this patent v UNITED STATES PATENTS Number Name Date 1,402,880 Merriman Jan. 10, 1922 1,782,992 Johnson Nov. 25, 1930 2,335,066 Lamar 'Nov. 23, 1943 2,420,755 Mavor May 20, 1947 2,538,112 Maier Jan. 16, 1951 FOREIGN PATENTS Number Country Date Great Britain May 15, 1924 

